diff --git a/src/fsm.c b/src/fsm.c
index 882a2b4..411797d 100644
--- a/src/fsm.c
+++ b/src/fsm.c
@@ -545,7 +545,7 @@
  */
 const char *osmo_fsm_event_name(struct osmo_fsm *fsm, uint32_t event)
 {
-	static char buf[32];
+	static __thread char buf[32];
 	if (!fsm->event_names) {
 		snprintf(buf, sizeof(buf), "%"PRIu32, event);
 		return buf;
@@ -575,7 +575,7 @@
  */
 const char *osmo_fsm_state_name(struct osmo_fsm *fsm, uint32_t state)
 {
-	static char buf[32];
+	static __thread char buf[32];
 	if (state >= fsm->num_states) {
 		snprintf(buf, sizeof(buf), "unknown %"PRIu32, state);
 		return buf;
diff --git a/src/gb/gprs_ns.c b/src/gb/gprs_ns.c
index cee4885..c77ebb3 100644
--- a/src/gb/gprs_ns.c
+++ b/src/gb/gprs_ns.c
@@ -1552,7 +1552,7 @@
 
 const char *gprs_ns_ll_str(const struct gprs_nsvc *nsvc)
 {
-	static char buf[80];
+	static __thread char buf[80];
 	return gprs_ns_ll_str_buf(buf, sizeof(buf), nsvc);
 }
 
diff --git a/src/gsm/abis_nm.c b/src/gsm/abis_nm.c
index a4c0e41..3fb8f0f 100644
--- a/src/gsm/abis_nm.c
+++ b/src/gsm/abis_nm.c
@@ -939,7 +939,7 @@
 
 const char *abis_nm_dump_foh(const struct abis_om_fom_hdr *foh)
 {
-	static char foh_buf[128];
+	static __thread char foh_buf[128];
 	return abis_nm_dump_foh_buf(foh_buf, sizeof(foh_buf), foh);
 }
 
diff --git a/src/gsm/apn.c b/src/gsm/apn.c
index 88b45a4..a7074ea 100644
--- a/src/gsm/apn.c
+++ b/src/gsm/apn.c
@@ -31,7 +31,7 @@
 #define APN_OI_GPRS_FMT	"mnc%03u.mcc%03u.gprs"
 #define APN_GPRS_FMT	"%s.mnc%03u.mcc%03u.gprs"
 
-static char apn_strbuf[APN_MAXLEN+1];
+static __thread char apn_strbuf[APN_MAXLEN+1];
 
 char *osmo_apn_qualify_buf(char *buf, size_t buf_len, unsigned int mcc, unsigned int mnc, const char *ni)
 {
diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c
index 26f7944..70eed15 100644
--- a/src/gsm/gsm0808_utils.c
+++ b/src/gsm/gsm0808_utils.c
@@ -611,7 +611,7 @@
 	return ret;
 }
 
-static char dbuf[256];
+static __thread char dbuf[256];
 
 /*! Dump LCLS parameters (GCR excluded) into string for printing.
  *  \param[out] buf caller-allocated output string buffer
@@ -1819,7 +1819,7 @@
  */
 const char *gsm0808_cell_id_name(const struct gsm0808_cell_id *cid)
 {
-	static char buf[64];
+	static __thread char buf[64];
 	return gsm0808_cell_id_name_buf(buf, sizeof(buf), cid);
 }
 
@@ -1829,7 +1829,7 @@
  */
 const char *gsm0808_cell_id_name2(const struct gsm0808_cell_id *cid)
 {
-	static char buf[64];
+	static __thread char buf[64];
 	return gsm0808_cell_id_name_buf(buf, sizeof(buf), cid);
 }
 
@@ -1886,7 +1886,7 @@
  * See also gsm0808_cell_id_list_name_buf(). */
 const char *gsm0808_cell_id_list_name(const struct gsm0808_cell_id_list2 *cil)
 {
-	static char buf[1024];
+	static __thread char buf[1024];
 	gsm0808_cell_id_list_name_buf(buf, sizeof(buf), cil);
 	return buf;
 }
@@ -1913,7 +1913,7 @@
 
 const char *gsm0808_channel_type_name(const struct gsm0808_channel_type *ct)
 {
-	static char buf[128];
+	static __thread char buf[128];
 	return gsm0808_channel_type_name_buf(buf, sizeof(buf), ct);
 }
 
diff --git a/src/gsm/gsm23003.c b/src/gsm/gsm23003.c
index a97ed07..4cc2671 100644
--- a/src/gsm/gsm23003.c
+++ b/src/gsm/gsm23003.c
@@ -107,7 +107,7 @@
  */
 const char *osmo_mcc_name(uint16_t mcc)
 {
-	static char buf[8];
+	static __thread char buf[8];
 	return osmo_mcc_name_buf(buf, sizeof(buf), mcc);
 }
 
@@ -158,7 +158,7 @@
  */
 const char *osmo_mnc_name(uint16_t mnc, bool mnc_3_digits)
 {
-	static char buf[8];
+	static __thread char buf[8];
 	return osmo_mnc_name_buf(buf, sizeof(buf), mnc, mnc_3_digits);
 }
 
@@ -182,7 +182,7 @@
  */
 const char *osmo_plmn_name(const struct osmo_plmn_id *plmn)
 {
-	static char buf[16];
+	static __thread char buf[16];
 	return osmo_plmn_name_buf(buf, sizeof(buf), plmn);
 }
 
@@ -193,7 +193,7 @@
  */
 const char *osmo_plmn_name2(const struct osmo_plmn_id *plmn)
 {
-	static char buf[16];
+	static __thread char buf[16];
 	return osmo_plmn_name_buf(buf, sizeof(buf), plmn);
 }
 
@@ -230,7 +230,7 @@
  */
 const char *osmo_lai_name(const struct osmo_location_area_id *lai)
 {
-	static char buf[32];
+	static __thread char buf[32];
 	return osmo_lai_name_buf(buf, sizeof(buf), lai);
 }
 
@@ -265,7 +265,7 @@
  */
 const char *osmo_cgi_name(const struct osmo_cell_global_id *cgi)
 {
-	static char buf[32];
+	static __thread char buf[32];
 	return osmo_cgi_name_buf(buf, sizeof(buf), cgi);
 }
 
@@ -276,7 +276,7 @@
  */
 const char *osmo_cgi_name2(const struct osmo_cell_global_id *cgi)
 {
-	static char buf[32];
+	static __thread char buf[32];
 	return osmo_cgi_name_buf(buf, sizeof(buf), cgi);
 }
 
@@ -320,7 +320,7 @@
  */
 const char *osmo_gummei_name(const struct osmo_gummei *gummei)
 {
-	static char buf[32];
+	static __thread char buf[32];
 	return osmo_gummei_name_buf(buf, sizeof(buf), gummei);
 }
 
diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c
index c2c19cf..c97337b 100644
--- a/src/gsm/gsm48.c
+++ b/src/gsm/gsm48.c
@@ -203,7 +203,7 @@
  */
 const char *osmo_rai_name(const struct gprs_ra_id *rai)
 {
-	static char buf[32];
+	static __thread char buf[32];
 	return osmo_rai_name_buf(buf, sizeof(buf), rai);
 }
 
@@ -502,7 +502,7 @@
  */
 const char *osmo_mi_name(const uint8_t *mi, uint8_t mi_len)
 {
-	static char mi_name[10 + GSM48_MI_SIZE + 1];
+	static __thread char mi_name[10 + GSM48_MI_SIZE + 1];
 	return osmo_mi_name_buf(mi_name, sizeof(mi_name), mi, mi_len);
 }
 
@@ -1150,7 +1150,7 @@
  */
 const char *gsm48_pdisc_msgtype_name(uint8_t pdisc, uint8_t msg_type)
 {
-	static char namebuf[64];
+	static __thread char namebuf[64];
 	return gsm48_pdisc_msgtype_name_buf(namebuf, sizeof(namebuf), pdisc, msg_type);
 }
 
@@ -1303,7 +1303,7 @@
  */
 const char *osmo_gsm48_classmark_a5_name(const struct osmo_gsm48_classmark *cm)
 {
-	static char buf[128];
+	static __thread char buf[128];
 	return osmo_gsm48_classmark_a5_name_buf(buf, sizeof(buf), cm);
 }
 
diff --git a/src/gsm/gsm_utils.c b/src/gsm/gsm_utils.c
index 07f053c..f154c2b 100644
--- a/src/gsm/gsm_utils.c
+++ b/src/gsm/gsm_utils.c
@@ -897,7 +897,7 @@
 
 char *osmo_dump_gsmtime(const struct gsm_time *tm)
 {
-	static char buf[64];
+	static __thread char buf[64];
 	return osmo_dump_gsmtime_buf(buf, sizeof(buf), tm);
 }
 
diff --git a/src/gsm/rsl.c b/src/gsm/rsl.c
index 0409734..3be0111 100644
--- a/src/gsm/rsl.c
+++ b/src/gsm/rsl.c
@@ -264,7 +264,7 @@
  */
 const char *rsl_chan_nr_str(uint8_t chan_nr)
 {
-	static char str[20];
+	static __thread char str[20];
 	return rsl_chan_nr_str_buf(str, sizeof(str), chan_nr);
 }
 
diff --git a/src/msgb.c b/src/msgb.c
index 940135f..4edbdf3 100644
--- a/src/msgb.c
+++ b/src/msgb.c
@@ -511,7 +511,7 @@
  */
 const char *msgb_hexdump(const struct msgb *msg)
 {
-	static char buf[4100];
+	static __thread char buf[4100];
 	return msgb_hexdump_buf(buf, sizeof(buf), msg);
 }
 
diff --git a/src/sim/core.c b/src/sim/core.c
index 63b3000..b93633c 100644
--- a/src/sim/core.c
+++ b/src/sim/core.c
@@ -300,8 +300,7 @@
 
 char *osim_print_sw(const struct osim_card_hdl *ch, uint16_t sw_in)
 {
-	/* FIXME: do we want to mark this as __thread? */
-	static char sw_print_buf[256];
+	static __thread char sw_print_buf[256];
 	return osim_print_sw_buf(sw_print_buf, sizeof(sw_print_buf), ch, sw_in);
 }
 
diff --git a/src/socket.c b/src/socket.c
index 37976e2..1e303bf 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -824,7 +824,7 @@
  */
 const char *osmo_sock_get_name2(int fd)
 {
-	static char str[OSMO_SOCK_NAME_MAXLEN];
+	static __thread char str[OSMO_SOCK_NAME_MAXLEN];
 	osmo_sock_get_name_buf(str, sizeof(str), fd);
 	return str;
 }
diff --git a/src/utils.c b/src/utils.c
index 59dc816..c38f530 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -41,7 +41,7 @@
  *
  * \file utils.c */
 
-static char namebuf[255];
+static __thread char namebuf[255];
 
 /*! get human-readable string for given value
  *  \param[in] vs Array of value_string tuples
@@ -219,7 +219,7 @@
 	return nibblepos >> 1;
 }
 
-static char hexd_buff[4096];
+static __thread char hexd_buff[4096];
 static const char hex_chars[] = "0123456789abcdef";
 
 /*! Convert binary sequence to hexadecimal ASCII string.
@@ -492,7 +492,7 @@
  * sizeof(uint64_t), only the least significant bytes of value are encoded. */
 uint8_t *osmo_encode_big_endian(uint64_t value, size_t data_len)
 {
-	static uint8_t buf[sizeof(uint64_t)];
+	static __thread uint8_t buf[sizeof(uint64_t)];
 	OSMO_ASSERT(data_len <= ARRAY_SIZE(buf));
 	osmo_store64be_ext(value, buf, data_len);
 	return buf;
@@ -908,7 +908,7 @@
  */
 const char *osmo_str_tolower(const char *src)
 {
-	static char buf[128];
+	static __thread char buf[128];
 	osmo_str_tolower_buf(buf, sizeof(buf), src);
 	return buf;
 }
@@ -967,7 +967,7 @@
  */
 const char *osmo_str_toupper(const char *src)
 {
-	static char buf[128];
+	static __thread char buf[128];
 	osmo_str_toupper_buf(buf, sizeof(buf), src);
 	return buf;
 }